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ARM: dma: Drop __GFP_COMP for iommu dma memory allocations 

__iommu_alloc_buffer wants to split pages after allocation in order to
reduce the memory footprint. This does not work well with __GFP_COMP
pages, so drop this flag before allocation

One failure example is snd_malloc_dev_pages call dma_alloc_coherent with
__GFP_COMP.

Signed-off-by: Richard Zhao <rizhao@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
hifive-unleashed-5.1
Richard Zhao 2013-06-20 20:31:00 +08:00 committed by Marek Szyprowski
parent 63c181922f
commit 5b91a98c61
1 changed files with 9 additions and 0 deletions
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9
arch/arm/mm/dma-mapping.c
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@ -1328,6 +1328,15 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
if (gfp & GFP_ATOMIC)
return __iommu_alloc_atomic(dev, size, handle);
/*
* Following is a work-around (a.k.a. hack) to prevent pages
* with __GFP_COMP being passed to split_page() which cannot
* handle them. The real problem is that this flag probably
* should be 0 on ARM as it is not supported on this
* platform; see CONFIG_HUGETLBFS.
*/
gfp &= ~(__GFP_COMP);
pages = __iommu_alloc_buffer(dev, size, gfp, attrs);
if (!pages)
return NULL;